Zygogynum schramii Vink, 2016

Vink, W., 2016, The Winteraceae of the Old World. VIII. Some Zygogynum species from New Guinea, Blumea 61 (1), pp. 41-50 : 48-49

13. Zygogynum schramii Vink , sp. nov. — Fig. 1

Zygogynum schramii Vink. — Type: Vink BW 8458 (holo L; iso A, BO, CANB, K, LAE, MAN n.v.).

Etymology. This species is named in honour of Ferdinand August Willem (Wim) Schram, 2 Aug. 1928 (Batavia) – 6 Apr. 2012 (Amsterdam), forest ranger and collector at the Forestry Herbarium at Manokwari, West New Guinea 1953–1962, who also took part in the survey that yielded the type material. See Flora Malesiana I-5, 1958: CCCXIX, and I-8, 1974: LXXXVII – LXXXVIII (photo).

Tree 12 m high, dbh 10 cm. Branchlets rather slender, brown. Leaves confined to the end of branchlets; petiole 10–15 mm long, almost flat to rounded above, rounded below, brown; blade obovate to oblanceolate, 9–26 by 4.5–7 cm, chartaceous, in sicco light brown to purplish grey below; apex broadly acute to obtuse and ultimately up to 1 cm rounded broad-acuminate, base narrowly acute; midrib impressed above, prominent below; secondary nerves at 50–70° with midrib, arcingly joined at some distance from margin, distinct above, prominulous below. On lower surface only stomata white, solitary, well-spaced, not over the most prominent secondary nerves; oil cells widely scattered. Inflorescences with 3–4 partial inflorescences, these 1–3 cm long, with thin axes, 1–5-flowered, if more than 1-flowered flowers inserted on main axis; empty bracts below inflorescence 1–5; pedicels in bud 3–13 mm long. Only buds known. Calyx (2–)3(–4)-lobed, thin, smooth. Petals 6–7, free. Stamens 33–39; thecae apically slightly separated to touching; connective not prolonged. Carpels 1(–2); stigma as long as carpel apex and adaxially descending almost to base of carpel; ovules 54–64. Fruitlets a soft berry, globose, 16– 20 mm diam, green, later greenish white and red; base abruptly 2–3 mm obconical; fruitwall without brachysclereids; pulpa also between seeds. Seeds several, obovoid, c. 3–4 mm long; testa thin, brittle, pusticularly ribbed.

Distribution — Papua: Sidoarsi Mts (only known from type).

Ecology — Primary forest at 660 m altitude. Flowerbuds and fruits in May.

Specimens examined. INDONESIA, Papua, Kab. Sarmi, Sidoarsi Mts, Vink

BW 8458 (A, BO, CANB, K, L, LAE ), 660 m alt.

Notes — The six petals are inserted in one series; if the 7th petal is present, this is in the second series.Although in 5 buds only solitary carpels were seen, the only fruit available is bicarpellate, the two fruitlets coherent by interwoven cells of the adaxial stigma parts.

Zygogynum schramii differs from Z. longifolium by the small inflorescences, the long stigma, and the high number of stamens. Zygogynum archboldianum has a comparable long stigma, but it has many carpels and coriaceous leaves.

Figures

Fig. 1 Carpels, all with ventral side to the left, and at the same magnification. – a. Zygogynum archboldianum; b. Z. bosavicum; c. Z. clemensiae; d. Z. cruminatum; e. Z. cyclopensis; f. Z. ledermannii; g, g'. Z. longifolium; j. Z. megacarpum; h. Z. montanum; i. Z. oligocarpum; k, k'. Z. polyneurum; l. Z. schramii; m. Z. sororium; n. Z. staufferianum; o. Z. umbellatum (a. Brass 12712; b. LAE 58822; c. Clemens 4596; d. LAE 69143; e. Royen & Sleumer 6396; f. Takeuchi 6212; g. Vink BW 8413; g'. Robbins 2004; j. Burley & Ismail 4618; h. LAE 61131; i. Schlechter 16470; k, k'. Jacobs 9489; l. Vink BW 8458; m. Ledermann 11898; n. Balgooy 968; o. Boden Kloss s.n.).